1. Field of the Invention
The present invention relates to a sound direction estimation device, a sound processing system, a sound direction estimation method, and a sound direction estimation program.
2. Description of Related Art
In the related art, a sound direction estimating technique of estimating a direction of a sound source from multiple sound signals has been proposed. The sound direction estimating technique is one of means for acquiring information on surrounding environments. The estimated sound direction is used, for example, as a condition for allowing a robot to determine an operation thereof. Accordingly, application of such a technique for work support or remote control in dangerous places and the like has been attempted.
In recorded sound signals, noise such as an operation sound of a piece of equipment such as an air conditioner or wind noise is superimposed on a target sound such as a speech uttered by a person or music. This noise serves as a cause of lowering estimation accuracy of a sound direction of a target sound. Therefore, reduction of an influence of noise on estimation of a sound direction has been proposed.
For example, Japanese Unexamined Patent Application, First Publication No. 2010-281816 (Patent Document 1) discloses a sound direction estimation device that calculates a correlation matrix of input sound signals, calculates eigenvectors using the calculated correlation matrix and a correlation matrix of noise, and estimates a sound direction using the calculated eigenvectors.
Japanese Unexamined Patent Application, First Publication No. 2012-042465 (Patent Document 2) discloses a sound direction estimation device that identifies a type of a sound source based on sound feature values of input sound signals, calculates a correlation matrix of the identified type of sound signals, and estimates a sound direction using calculated eigenvectors. In both the sound direction estimation devices disclosed in Patent Document 1 and Patent Document 2, it is necessary to acquire noise correlation matrixes or sound feature values for each type of sound source in advance.